Two isostructural 3-(5-aryloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(thiophen-2-yl)prop-2-en-1-ones: disorder and supramolecular assembly

Abstract

Two new chalcones containing both pyrazole and thiophene substituents have been prepared and structurally characterized. 3-(3-Methyl-5-phenoxy-1-phenyl-1H-pyrazol-4-yl)-1-(thiophen-2-yl)prop-2-en-1-one, C23H18N2O2S (I), and 3-[3-methyl-5-(2-methylphenoxy)-1-phenyl-1H-pyrazol-4-yl]-1-(thiophen-2-yl)prop-2-en-1-one, C24H20N2O2S (II), are isomorphous as well as isostructural, and in each the thiophene substituent is disordered over two sets of atomic sites having occupancies 0.844 (3) and 0.156 (3) in (I), and 0.883 (2) and 0.117 (2) in (II). In each structure, the molecules are linked into sheets by a combination of C—H...N and C—H...O hydrogen bonds. Comparisons are made with some related compounds.

Keywords

• heterocyclic compounds
• pyrazoles
• crystal structure
• disorder
• molecular conformation
• hydrogen bonding
• supramolecular assembly